                        课程
                    
                        /前端开发
                        
                            /JavaScript
                        
                        /JS动画效果

不明白错在哪，打开页面不滑动

<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>滑出导航栏</title>
<style>
body,div,span{
   margin: 0;
   padding: 0;
}
#div1{
   width: 200px;
   height: 200px;
   background: red;
   position: relative;
   left :-200px;
   top:0;
}
#div1 span{
       width: 20px;
       height: 50px;
       background: blue;
       position: absolute;
       left: 200px;
       top:75px;
   }

</style>

<script type="text/javascript">
       window.onload=function(){

       var   oDiv=document.getElementById('divl');

       oDiv.onmouseover=function(){

       startMove(0);}

       oDiv.onmouseout=function(){

       startMove(-200);}

       }
       var timer=null;

       function startMove(iTarget){
           clearInterval(timer);
           var   oDiv=document.getElementById('divl');
           timer=setInterval(function()
           {   var speed=0;
           if(oDiv.offsetLeft>iTarget)
               {speed=-10;}
           else{speed=10;}
               if(oDiv.offsetLeft==iTarget)
                   {clearInterval(timer);}
               else
               {oDiv.style.left=oDiv.offsetLeft+speed+'px';}
           },30)
       }

</script>
<body>
<div id="div1"><span id="share">分享</span></div>
</body>
</html>